The Washington National Primate Research Center (WaNPRC) has an extensive commitment towards support of research in nonhuman primate model systems. As part of this commitment, the WaNPRC continues to acquire resources necessary to meet experimental objectives using the most relevant, healthiest, well-adapted animal model possible. Social contact is widely recognized as the most effective prevention and therapy for abnormal behavior in laboratory primates, but may need to be limited for certain experiments. Acquisition of modular enrichment caging will greatly improve the ability of the WaNPRC to meet standards for animal husbandry and enhance psychological well-being, in turn supporting biomedical research utilizing nonhuman primates. For subjects on restricted protocols, flexible socialization options will allow primates visual contact, limited physical contact through grooming bars, or full physical contact and socialization during certain study phases, as dictated by protocol requirements. This flexibility will allow for the maximum possible socialization throughout the course of the study, thereby promoting the primate's psychological well-being as mandated in the 1985 Amendment to the Animal Welfare Act. The proposed caging meets and exceeds current federal regulatory standards, guidelines and recommendations. Relevance: The addition of new caging with a variety of options for socialization will benefit a wide variety of biomedical research funded by NIH to improve the public health. The infrastructure to provide optimal animal care and the best possible animal model is essential for the operation of the Washington National Primate Research Center, and supports research projects across a broad portfolio, currently 72 different projects, which work toward important advances for human health.